The present invention relates to a security system for an electronic instrument for example a computer, and more particularly to such a security system which is automatically switched on to start a burglar alarm when the casing of the electronic instrument is opened by an intruder.
In order to prohibit other people from stealing storage data from one""s personal computer, the boosting program of the computer may be encrypted. However, the encrypted boosting program may easily be decrypted by a computer expert. In order to eliminate this problem, a cover shell may be provided and covered on the control panel of the computer to prevent others from operating the computer.
It is one object of the present invention to provide a security system for a computer which automatically detects opening/closing status of the casing of the computer. It is another object of the present invention to provide a security system for a computer which can be used in any of a variety of existing computers. It is still another object of the present invention to provide a security system for a computer which automatically triggers burglar alarm when the casing of the computer is opened illegally. To achieve these and other objects of the present invention, there is provided a security system, which comprises a logic circuit controlled to output an alarm signal to audio alarm means, a locating member, for example, a nut provided at a computer""s shell, a press means, for example, a screw threaded into the nut, a switch installed in the nut and forced by the screw to switch off the logic circuit, the switch comprising an electrical connector connected to the logic circuit, a rod member installed in the nut and forced by the screw to switch off the electrical connector, and a spring member which pushes the rod member outwards when the screw is disconnected from the nut, causing the electrical connector to be switched on by the rod member.